Circular function and Mathematical function

Circular function noun - Function of an angle expressed as a ratio of the length of the sides of right-angled triangle containing the angle.

Mathematical function and circular function are semantically related. In some cases you can use "Mathematical function" instead a noun phrase "Circular function".

Mathematical function noun - Mathematics) a mathematical relation such that each element of a given set (the domain of the function) is associated with an element of another set (the range of the function.

Circular function and mathematical function are semantically related. Sometimes you can replace phrase "Circular function" with "Mathematical function", this phrases are similar.